1. Technical Field
The present invention relates to a liquid ejecting head unit and a liquid ejecting apparatus, and more particularly to those which are useful when applied to a system in which a liquid flow channel unit for supplying a liquid reserved in a liquid supply source to a head body is disposed on the way to a flow channel reaching the head body.
2. Related Art
As a representative example of the liquid ejecting head, for example, an ink jet recording head in which ink droplets are discharged from a nozzle opening by using a pressure created by a piezoelectric element displacement is known. In the ink jet recording head according to the related art, ink is supplied from the liquid supply source such as an ink cartridge filled with ink to the head body, and the ink supplied from the head body is discharged from a nozzle by driving a pressure generating means such as a piezoelectric element or a heating element. For example, by inserting an ink supply needle into the ink cartridge, ink in the ink cartridge is introduced to a pressure chamber side of the head body from an introducing hole of the ink supply needle.
Here, there is also provided a system in which the liquid flow channel unit is provided on the way to the flow channel which supplies ink from the liquid supply source such as the ink cartridge to the head body and constitutes the inkjet recording head unit along with the head body. The liquid flow channel unit, for example, fulfills a damper function which suppresses a pressure fluctuation such as a pulsation of liquid occurring due to inertial force acting on a liquid in a case in which the ink jet recording head unit is moved with a carriage. For this reason, the liquid flow channel unit is configured to form a pressure chamber in a flow channel by covering an opening portion in a body member having a liquid flow channel formed therein by a film member and, in a case in which a pulsation of liquid in the pressure chamber has occurred, to absorb the pulsation through a warp of the film member.
Furthermore, there is a related art which discloses a liquid flow channel unit having such a damper function (see, for example, Japanese Patent No. 3,606,282).
In the meantime, the liquid flow channel unit according to the related art is separately provided with a head body and is connected to the head body through another flow channel such as a tube. That is, it wan not configured to supply the liquid discharged from the liquid flow channel unit directly to a reservoir as a common liquid chamber of the head body. As a result, the ink jet recording head unit according to the related art having a liquid flow channel unit is forced to be large-scaled by as much.
Furthermore, such a problem is not limited to an ink jet recording head unit and is similarly present in a liquid ejecting head unit which ejects liquid other than ink.